Pump construction

ABSTRACT

A pump for viscous materials has a pair of cylinders each of which is provided with a working end which receives viscous material, and with a remote end. Pistons are reciprocable in each of the cylinders and a casing bridges the remote ends and is provided with one or two interior chambers. One or two rollers are turnably mounted in these chambers and ropes or the like are trained about the single or several rollers and connected at one end with one of the pistons and, if there is a single rope, connected at the other end with the other piston or, if there are two ropes, connected at the other end with a control piston which is slidable in a separate channel of the respective cylinder, or with a single control piston which is slidable in a separate channel of one of the cylinders.

United States Patent 1191 Schiirenberg et al.

[ Dec. 11, 1973 PUMP CONSTRUCTION 97,698 12/1869 Reynolds 417/339 1 1 M Schfirwberg, 1 321??? 311318 3125111113311: 1111311113: ill/3 Wenlel, 3,189,078 6/1965 DaVlClSSOn... 417 343 WanneE1ckel, both of Germany [73] Assignee: Torkret GmbH, Essen, Germany Primary ExaminerWilliam L. Freeh [22] Filed: July 15, 1971 Attorney-M1chael S. Striker [21] Appl. N0.: 162,966 [57} ABSTRACT A pump for viscous materials has a pair of cylinders [30] Foreign Apphcatmn-Pnomy Data each of which is provided with a working end which 1971 Gelmany P 21 06 713-0 receives viscous material, and with a remote end. Pistons are reciprocable in each of the cylinders and a [52] US. Cl .1 92/137, 92/168, 417/343 casing bridges the remote ends and is provided with [51] hit. Cl. F01) 9/00 one or two interior chambcrs o or two ll are [58] Field of Search 417/343, 393, 415, mmably mounted in these chambers and ropes the 417/529 92/68 168; 277/581 like are trained about the single or several rollers and 102 connected at one end with one of the pistons and, if there is a single rope, connected at the other end with [56] References C'ted the other piston or, if there are two ropes, connected UNITED ST PATENTS at the other end with a control piston which is slidable 194,377 8/1877 Schenck 92 137 x in a s para nn of h respective cylinder, or 729,210 5/1903 Norton..... 92/68 X with a single control piston which is slidable in a sepa- 3,267,316 9 Graham 92/137 X rate channel of one of the cylinders. 3,267,817 8/1966 Adams 92/137 X 3,514,113 5/1970 Weiswurm 92/168 X 7 Claims, 9 Drawing Figures *5 7 5 a I l I lw\\ \\\\ZL\\ PUMP CONSTRUCTION BACKGROUND OF THE INVENTION The present invention relates generally to pump'constructions, and more particularly to a pump for viscous materials. Still more particularly the present invention relates to a pump for such viscous materials as concrete.

It is already known to provide a pump of the general type in question in which two cylinders are provided each of which has a reciprocable piston which are coupled for joint movement. The working ends of the cylinders receive concrete or similar viscous material alternately via a controllable distributor, and the pistons alternately eject the received material into a pressure conduit or the like. While one piston performs its working stroke to eject the material, the other piston performs its suction stroke. A supply hopper supplies the material to the cylinders and is provided with two open-' ings each of which communicates with one of the cylinders and which are alternately closed and opened by the distributor. One known construction provides for the reciprocation of the piston or pistons alternately due to the over and under pressure of the pressure medium in the cylinder associated with the piston. The force acting upon the piston during the suction stroke of the latter for sucking the material from the hopper into the cylinder whose piston performs the suction stroke, is limited by and to the underpressure produced by the pressure medium in the cylinder whose piston performs the suction stroke. If there is any leakage in the hydraulic system, this will be immediately translated in terms of improper operation of the pump. Furthermore, the seal of the piston has a tendency, when subjected to under pressure, to contract which means that its sealing effectiveness is substantially reduced. If

in this manner quantities of the viscous material to be pumped are permitted to enter the hydraulic system, the entire unit is subjected not only to malfunctions but also to very high wear.

Another construction utilizes a pair of ropes each of which is connected with one of the pistons and has its other end connected with a winch which is mounted in that portion of the cylinder remotefrom the working end and which is turnable by a shaft extending to the interior of the cylinder. The two winches are connected at the exterior by a transmission or the like. This arrangement has the significant disadvantage that when the rope is relaxed, a relatively large mass must be accelerated, namely the two winches with the associated transmission and other components. This frequently leads to breakage of the ropes, and in addition it is clear that only a relatively limited space is available for these various components in the cylinders so that the diameter of the ropes must be limited under all circumstances, thereby further facilitating the danger of breakage.

It is clear, therefore, that the existing state of the art is not entirely satisfactory and is in need of improvement.

SUMMARY OF THE INVENTION It is, therefore, a general object of the present invention to provide such improvement.

More particularly it is an-object of the present invention to provide an improved pump construction of the type under discussion which is not possessed of the disadvantages outlined above with respect to the prior art.

Still more particularly it is an object of the present invention to provide such a pump construction in which the pistons are firmly and reliably controlled as to their reciprocatory movements.

An additional object of the invention is to provide such a pump construction in which themeans for ef fecting such control require relatively little space and in which a reliable sealing effect with respect to the various components involved is obtained.

In pursuance of the above objects, and of others which will become apparent hereafter, one feature of the invention resides in a pump for viscous materials, particularly for concrete, which comprises according to one embodiment, a pair of cylinders each having a working end adapted to receive viscous material, and a remote end. A pair of pistons are also provided, each being reciprocable in one of the cylinders. Wall means defines an enclosure which communicates with bothof the remote ends and roller means is turnably joumalled in this enclosure. Elongated flexible means is trained about the roller means and connected with the pistons for effecting the reciprocation of the latter.

With this construction the aforementioned objects are achieved. The rollers require but little space and no sealing difficulties are experienced. When one of the. pistons is subjected to fluid pressure to move it from its retracted to its working position, the other piston is necessarily moved in the opposite direction, beingcoupled with the first-mentioned piston by the rope or ropes. This means that the second piston performs its suction stroke and draws the material to be pumped into its associated cylinder, and during the next reciprocatory movement during which it performs its working stroke, the first-mentioned piston performs its own suction stroke.

According to a further concept of the invention a sin gle roller may be utilized in the enclosure, and the remote ends of the cylinders may be provided with respective openings through which opposite end portions of a single rope trained about the roller, will pass. Sealing means will then be provided for sealing these openings with respect to the end portions of the rope but while permitting the rope freedom of sliding movement through these openings. The opposite end portions of the rope will of course be connected with the respective pistons and this construction is particularly simple because it requires nothing more but a sealing arrangement for the aforementioned openings.

According to a further embodiment of the invention the enclosure may be subdivided into two chambers each having a roller joumalled therein. A single rope may be trained about the. two rollers and be connected at its opposite end portions with the respective pistons. The wall which subdivides the enclosure into the two chambers may be provided with an aperture through which the rope passes and which is again sealed by suitable sealing means. This construction is also exceedingly simple in that only a single seal is provided in the aperture for the wall subdividing the enclosure into the two chambers.

The invention provides also for a further embodiment according to which the enclosure is again subdivided with a roller being joumalled in each chamber provided in this manner. However, here two ropes are utilized each trained about one of the rollers and connected with one end to one of the pistons and with the other end to a control piston located in a specially provided channel of the associated cylinder. This construction is highly advantageous in that it is not possible for the rope to become relaxed. Here the rollers are mounted on shafts which extend to the exterior of the enclosure and are provided with chain sprockets or the like which are connected with one another via an endless chain carrying an abutment in whose path of movementis located an end switch which is controlled by the abutment on contact therewith, so that the end position of the respective working and suction stroke of each piston is thereby controlled by reversing the direction of movement of the chain.

Still another embodiment of the invention provides for a construction in which the enclosure is again subdivded into two chambers, each chamber having a roller journalled therein. Here, however, a single rope is provided which is trained about both rollers and whose opposite ends are connected to the respective pistons. One of the cylinders is provided with a special channel in which a control piston is reciprocable and an intermediate portion of the rope is connected with this control piston which latter hydraulically separates the working pistons of the cylinders from one another.

It is also advantageous according to a concept of the present invention that the circumferential surfaces of the sealing elements utilized are under the operating pressure of the pressure medium used for effecting reciprocation of the pistons, in order to obtain a tight engagement of the seal with the rope or the like. The seals are advantageously mounted in casings which are connected via channels or the like with the source of pressure fluid.

The novel features which are considered as charac teristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary sectioned view of one embodiment of the invention;

FIG. 2 is a view similar to FIG. 1 but illustrating a further embodiment of the invention;

FIG. 3 is a sectioned view illustrating one sealing arrangement according to the invention;

FIG. 4 is a view similar to FIG. 3 but illustrating a further sealing arrangement;

FIG. 5 is a view similar to FIG. 3 illustrating an additional sealing arrangement;

FIG. 6 is a view similar to FIG. 1 illustrating a further embodiment;

FIG. 7 is a view taken on line VII-VII of FIG. 6;

FIG. 8 is a fragmentary detail view of the exterior control of the embodiment in FIGS. 6 and 7; and

FIG. 9 is a view similar to FIG. 1 illustrating an additional embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail, and firstly the embodiment in FIG. 1, it will be seen that here reference numerals 1 and 2 identify two cylinders of a pump whose other components are not illustrated in detail.

By other components is meant the supply hopper and the like for the material, and the conduits which receive the material pumped by the pump. Accommodated in the cylinders l and 2 are two working pistons 3 and 4 for reciprocation therein. The left-hand side of the cylinders 1 and 2 must be understood to be connected with a supply hopper as well as with a pressure conduit which receives material entering the cylinders from the supply hopper. This is already known and is not believed to require further discussion, particularly in view of the fact that it does not in itself form a part of the present invention. The left-hand end portions of the cylinders l and 2 are thus to be considered the working ends. Wall means in form ofa housing 10 is directly connected with the right-hand or remote end portions of the cylinders l and 2 forming a single enclosure or enclosed internal space and being flanged to the cylinders. .Iournalled for rotation in the enclosure are two rollers 6 and 7 about which a single rope 5 is trained. The opposite end portions of the rope 5 are connected with the working pistons 3 and 4, respectively. A separating wall 8 is provided which subdivides the enclosure constituted by the housing 10 into two chambers and is provided with an opening through which the rope 5 passes, and which is sealed by a sealing construction 9 which permits sliding movement of the rope 5.

The embodiment in FIG. 2 differs from that of FIG. 1 in that the housing 10 is of one-piece construction and only a single roller 6 is journalled for rotation in it. Here the rope 5 passes through two sealing constructions 9 which are provided to seal openings in the end walls of the cylinders 1 and 2 and through which the rope 5 again passes. In other respects the embodiment of FIG. 2 is the same as that in FIG. 1.

FIG. 3 shows in detail one sealing construction for use in the preceding embodiments. It is provided with a casing 11 and a sealing sleeve 12 through which the rope 5 passes. Channels 13 establish communication of the casing 11 with the non-illustrated source of pressure medium for effecting reciprocation of the working pistons, so that the circumference of the sealing sleeve 12 is subjected to the pressure of the pressure medium and thus is firmly pressed against the rope 5 in order to obtain good sealing effectiveness. The pressure force with which the sleeve 12 engages the rope 5 is so selected as to obtain a reliable sealing effect while on the other hand keeping the wear resulting from friction to a minimum.

FIG. 4 shows a further sealing construction intended particularly for use in the embodiment of FIG. 1 and connected via a channel 13 directly with the pressure side of the pump. The illustration in FIG. 4 is believed to be self-explanatory.

FIG. 5 shows still another embodiment of the sealing construction intended specifically for use in the embodiment of FIG. 2 and also connected via a channel 13 directly with the pressure side of the pump. Again, the embodiment of FIG. 5 is believed to be selfexplanatory. Let it be noted that two of the sleeves 12 are utilized in this construction.

It will be appreciated that in all embodiments the sealing effectiveness and the reliability and lifetime of the seal depends to a large extent not only on the sleeve 12, but also upon the characteristics of the rope 5. Because of the high tensile forces to be transmitted via the rope 5 it is preferred to use a wire rope with a synthetic plastic jacket, or else a wire rope which is accommodated in a smooth-surfaced hose.

A further embodiment of the invention is illustrated in FIG. 6 wherein two ropes 5 are provided, each connecting the respective working pistons 3 and 4 with a control piston 14 having a substantially smaller surface area at its end face than the pistons 3 and 4 and guided in a separate channel of the respective cylinders 1 and 2. FIG. 7 shows particularly clearly that the rollers 6 and 7 each of which has one of the ropes 5 trained thereabout, are provided on shafts 16 which extend to the exterior of the housing 10 which is here again subdivided into two chambers by the dividing wall 8. At the outer side of the housing 10 the shafts 16 are provided with suitable motion-transmitting means, here in form of chain sprockets 17 which engage an endless chain 18 and are thereby connected with one another in order to obtain enforced unity of movement of the pistons 3 and 4. A control or abutment member 19 is provided on the chain 18 and is associated with an end switch 20 so positioned that it is located in the path of movement of the abutment 19 and will be operated by the same, whereby a direction reversal of the chain 18 and thereby of the strokes of the pistons 3 and 4, respectively, is obtained.

The embodiment of FIG. 9, finally, utilizes again the same components as before, except that here only one rope 5 is provided and only one separate channel 22 in which only a single control piston 21 is accommodated. The opposite end portions of the rope 5 are connected with the working pistons 3 and 4, respectively, and an intermediate portion of the rope 5 passes through the channel 22 and is connected with the control piston 21 which separates the working pistons 3 and 4 hydraulically from one another. The housing is again identified with reference numeral 10, being subdivided into two chambers by the wall 8 and each of the chambers accommodating a roller 7. The roller 6 is here located in the region of the opposite or working ends of the cylinders l and 2 and the rope is trained about it with its intermediate portion.

In all embodiments here illustrated and discussed,

A and it should be noted that they are of course only exemplary and not to be considered limiting, it is pointed out that the rollers as well as the various components necessary for reversing the direction of reciprocation of the working pistons 3 and 4, are only of relatively small mass so that their direction can be reversed simply and without difficulties, and without requiring substantial energies. Furthermore, no particular sealing problems are encountered in these constructions, due to the high sealing effectiveness obtained with the various embodiments, so that the wear is significantly reduced and the devices have a greatly improved lifetime.

It'will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a pump construction, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, all such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended:

1. In a pump for viscous materials, particularly for concrete, in combination, a pair of cylinders each having a working end adapted to receive viscous material, and a remote end, said cylinders also having a separate channel communicating with both cylinders; a control piston in said channel and fluid-tightly separating said cylinders; a pair of pistons each reciprocable in one of said cylinders; wall means fastened to said cylinders and defining two enclosed chambers each associated with one of said remote ends; roller means turnably journalled in said space and comprising two rollers each mounted in one of said chambers; and elongated flexible rope means trained about said roller means and having end portions connected with said pistons for effecting the reciprocation of the same, and an intermediate portion connected with said control piston.

2. In a pump for viscous materials, particularly for concrete, in combination, a pair of cylinders each having a working end adapted to receive viscous material, and a remote end, each of said cylinders having a separate channel and a control piston slidable therein; a pair of pistons each reciprocable in one of said cylinders; wall means fast with said cylinders and defining an enclosed internal space which is subdivided in two chambers each associated with one of said cylinders and the respective channel; roller means turnably jour nalled in said space and comprising a pair of rollers each journalled in one of said chambers; and a pair of elongated flexible ropes each trained about one of said rollers and having spaced end portions respectively connected with the piston and the control piston of the associated cylinder.

3. In a pump as defined in claim 2; further comprising shafts mounting the respective rollers and extending to the exterior of said chambers; an endless motiontransmitting element; and coupling means coupling said shafts with said motion-transmitting element.

4. In a pump as defined in claim. 3, said element being a chain, and said coupling means comprising chain sprockets. 5. In a pump as defined in claim 4; further comprising an abutment carried by said chain, and a direction reversing switch adjacent said chain and adapted to be engaged by said abutment during movement of the same with said chain.

6. In a pump for viscous materials, particularly for concrete, in combination, a pair of cylinders each having a working end adapted to receive viscous material, and a remote end; a pair of pistons each reciprocable in one of said cylinders; wall means fastened to said cylinders and defining an enclosed internal space which communicates with both of said remote ends; roller means turnably journalled in said space; elongated flexible means trained about said roller means and connected with said pistons for effecting the reciprocation of the same; fluid-pressure actuatedsealing means sealing said elongated flexible means with. respect to said cylinders so as to maintain the latter fluidtightly sepacasing means accommodating said sealing means; and wherein said conduit means communicates with said casing means. 

1. In a pump for viscous materials, particularly for concrete, in combination, a pair of cylinders each having a working end adapted to receive viscous material, and a remote end, said cylinders also having a separate channel communicating with both cylinders; a control piston in said channel and fluid-tightly separating said cylinders; a pair of pistons each reciprocable in one of said cylinders; wall means fastened to said cylinders and defining two enclosed chambers each associated with one of said remote ends; roller means turnably journalled in said space and comprising two rollers each mounted in one of said chambers; and elongated flexible rope means trained about said roller means and having end portions connected with said pistons for effecting the reciprocation of the same, and an intermediate portion connected with said control piston.
 2. In a pump for viscous materials, particularly for concrete, in combination, a pair of cylinders each having a working end adapted to receive viScous material, and a remote end, each of said cylinders having a separate channel and a control piston slidable therein; a pair of pistons each reciprocable in one of said cylinders; wall means fast with said cylinders and defining an enclosed internal space which is subdivided in two chambers each associated with one of said cylinders and the respective channel; roller means turnably journalled in said space and comprising a pair of rollers each journalled in one of said chambers; and a pair of elongated flexible ropes each trained about one of said rollers and having spaced end portions respectively connected with the piston and the control piston of the associated cylinder.
 3. In a pump as defined in claim 2; further comprising shafts mounting the respective rollers and extending to the exterior of said chambers; an endless motion-transmitting element; and coupling means coupling said shafts with said motion-transmitting element.
 4. In a pump as defined in claim 3, said element being a chain, and said coupling means comprising chain sprockets.
 5. In a pump as defined in claim 4; further comprising an abutment carried by said chain, and a direction-reversing switch adjacent said chain and adapted to be engaged by said abutment during movement of the same with said chain.
 6. In a pump for viscous materials, particularly for concrete, in combination, a pair of cylinders each having a working end adapted to receive viscous material, and a remote end; a pair of pistons each reciprocable in one of said cylinders; wall means fastened to said cylinders and defining an enclosed internal space which communicates with both of said remote ends; roller means turnably journalled in said space; elongated flexible means trained about said roller means and connected with said pistons for effecting the reciprocation of the same; fluid-pressure actuated sealing means sealing said elongated flexible means with respect to said cylinders so as to maintain the latter fluidtightly separated from one another; a source of pressure fluid; and conduit means connecting said source with said sealing means whereby to effect pressure-actuation of the sealing action thereof.
 7. In a pump as defined in claim 6; further comprising casing means accommodating said sealing means; and wherein said conduit means communicates with said casing means. 